Ray, et al
That is the antenna and az/el tracking and receiving unit of the AN/GMD-1A. It was the mainstay of the military and the NWS until the 70's. We gave GMDs to numerous foreign countries. The sonds were made by VIZ.  I retired in the early 2000 but we were beginning to install the new equipment.  I put the first Intermet Corp. 7units in Jamaica and the Bahamas. Nice swan-song projects.  Early GPS sondes were made in Mexico with spotty reliability.  I guess they straightened things out at the KC depot.
Jeep K3HVG
 
 
 
On 10/06/2026 4:25 PM EDT Ray Fantini via MRCA <[email protected]> wrote:
 
 
Went back and looked, have a picture of the tracker dish.
 
Ray F/KA3EKH
 
 

From: [email protected] <[email protected]> on behalf of Ray Fantini via MRCA <[email protected]>
Sent: Tuesday, October 6, 2026 4:12 PM
To: [email protected] <[email protected]>; Al Klase <[email protected]>
Subject: Re: [MRCA] Radiosondes
 
 
It's amazing all the ways you can waste time on the internet! Before Fair Radio closed shop, they had a four- or five-foot dish on a tripod with a receiver built onto the back. Assume most people thought it was a radar dish and when I went and looked at it up close saw it was an automated tracker for what I would think was weather ballons being it was like 403 or 405 MHz
Completely unrelated but years ago I set up a system for capturing the old APT satellites on 137.5 MHz and just the other day had someone ask what the circularly polarized antenna and down converter they had picked up was for, along with seeing a lot of that old VHF stuff turn up but as far as I know that entire network is gone now with them pulling the plug on NOAA-15 last year.
 
Ray F/KA3EKH
 
 
 
 

From: [email protected] <[email protected]> on behalf of Al Klase via MRCA <[email protected]>
Sent: Monday, October 5, 2026 8:08 PM
To: [email protected] <[email protected]>
Subject: Re: [MRCA] Radiosondes
 
Fascinating!

73.
AL

On 05/10/2026 7:28 PM, Tim via MRCA wrote:
Speaking of Sondes....Here's a link to current radiosonde weather balloon ops worldwide.  They are at-altitude at 0000Z and 1200Z daily.  They actually launch about 45-60 minutes before that.  Major airports are the usual launch sites.
The ones out west here are RS41's that operate at 404 MHz, around 60 mw and I can receive the basic telemetry from a LONG distance away. Click on your local balloon and it shows all the data including its GPS coord's, current altitude, temp etc.  
Plot shows the track and predicted future track.  They usually get up to around 100,000' AMSL, often higher before they burst.  Then a long ride down on a parachute.  (fun fact:  from 105,000' the parachute has NO initial effect on the fall rate...very little air up there... LOL) 
Enjoy! https://sondehub.org/
Tim
N6CC
 
______________________________________________________________
MRCA mailing list
Home: http://mailman.qth.net/mailman/listinfo/mrca
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html